Water heater



T. D. PILCHER.

WATER HEATER.

APPLICATION FILED JULY 5.1921.

RENEWED OCT. 10,1922.

Patented Dec. 12, 1922.

I nm-entan Patented Dec. 12, 1922.

THOMAS D. PILCHER, OF WASHINGTON, DISTRICT OF COLUMBIA.

WATER HEATER.

Application filed July 5, 1921, Serial No. 482,505. Renewed October 10, 1922. Serial No. 593,658.

To all whom it may concern.

Be it known that I, THOMAS D. PILoHER, a citizen of the United States, residing at \Vashington, in the District of Columbia, have invented certain new and useful Improvements in ater Heaters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. I

The object of the invention generally is the provision of a heater wherein more of the generated heat energy than usual shall be transmitted to the medium to be heated and not be discharged to the atmosphere and wasted.

Specific-ally the object is the provision of an apparatus for heating water or other fluid wherein the current of the heat bearing medium employed, such as air and gases mingled with the products of combustion and raised to a high temperature, shall be retarded and caused to engage a relatively large area of heat receiving surface, but such retardation not be suflicient to injuriously impair the draft and cause the discharge of heated gases and smoke at the entrance end for such heat bearing medium.

In carrying out the invention use is made of the principle that fluids in motion, such as air and the like, tenaciously cling to the surfaces over which they move in frictional contact, following the irregularities and changes of direction of such surfaces, rather than at once passing to the open space or spaces adjacent such surfaces.

The invention consists in certain novelties of construction and in the combination of parts herein set forth and claimed.

The accompanying drawing illustrates an example of the embodimentof the invention, the parts being constructed and relatively combined according to the best of the several modes of procedure I have so far devised for the purpose.

Figure 1 is a vertical section in elevation of a hollow cylindrical tank for water and a hollow heating flue located concentrically or axially therein, parts at the top and bottom of said flue being broken away to show the interior.

Figure 2 is a view of the tank shown by Figure 1 and a slightly modified form or construction of the flue shown by Figure 1, the view being substantially the same except that the top part of the flue wall only is shown in section.

Referring to both figures, the parts common to both are designated by the same characters. A is a hollow cylindrical metallic tank either of wrought or castmetal having a tog perforated outwardly projecting circular ange B and a similar bottom perforated flange C to receive rivets. The interior of the tank is to contain water or other fluid to be heated, and to provide for the circulation of the fluid through a coil or closed pipe one end of said pipe D is secured in the wall-of the tank near the bottom thereof and the opposite end E is secured in the wall near the top end, the heated water passing out of the top of the tank at the end E and returning to the interior thereof through the end D, as is well known.

, Axially located relative to and within the tank is a hollow heating flue F of cast or wrought metal. Said flue at its ends may be exteriorly threaded at G G to receive threaded flanges H H of top and bottom heads I and J, said heads being circular in outline and perforated as shown. Rivets R passed through the perforations in the heads and the perforations in the flanges B and C of the tank close the ends of the tank and the heads hold the flue F in position.

Each of the flues has one or more hollow enlargement S intermediate its ends, two such enlargements being shown in each figure. In Figure 1 the lower, top, and intermediate parts of the flue. designated by T, U and V. are of the same diameter and the cross sectional areas the same. In Figure 2 the lower part W and the intermediate part X of the flue are of the shapes shown and each gradually increases in diameter upwardly so that the cross sectional areas of said parts at Y Y where they join the enlargements S, S are of greater cross sectiona area than at any section below.

It will be noted that each of the enlargements S gradually increases in diameter to its center and then gradually decreases in diameter to its discharge outlet.

It has been determined by experiments that to secure the requisite draft or flow of the heat carrying medium, as heated air mingled with the heated gases and other heated products of combustion, through the flue the same" must practically be unobstructed throughout its length and present an open passageway to the atmosphere.

' the two figures.

The mode of operation is as follows: The particles ofthe heat carrying me: dium, such as heated air, heated gases, and

other heated products of combustion, pass upwardly through the flue, inasmuch asucts of combustion, pass into an enlargement S they do not follow straight lines through the interior, but tenaciously cling to the interior surface and in the main follow the interior surface around to the discharge outlet, as shown by the arrows in Obviously, in such case heat is transmitted to relatively large areas of surfaces, and the walls'defining such surfaces being exteriorly in contact with the water or other fluid in the tank transmit heat to the same Therising current of the heat carrying medium, inasmuch as it spreads out on entering an enlargement S,

is retarded or decreased in velocity and more time is thus provided for transferring to the walls defining the enlargement the heat, or mode of motion defined as heat.

Heated water also rises relative to the cold water in a tank, as is well .known, consequently as the cross sectional areas of the tank at the dotted lines 1 are less than at the dotted line 2 the upwardly moving current of heated water is retarded and the same held for a longer period of time in contact with the heated surfaces Z of the enlargements S than otherwise would be the case, thus resulting in its receiving more heat or its temperature being raised.-

naeeaeo In practice the cross sectional areas of the parts of the flue T, Usand V, Figure 1, and parts W and X, Figure 2, as illustrated, are

of importance-that is, they .should be of Y the same cross sectional areas, Figure 1, or enlarged upwardly, Figure 2,'for if tapered upwardly and inwardly each would act as an injectorand discharge the current of the heat carrying medium through the enlargement S and prevent the same passing around the interior surface and in frictional contact therewith.

The apparatus as described can, of course, be applied in connection with any source of heat, as may be determined by special conditions, and at the election or choice of those skilled in the art.

What ll claim is:

1. A water heater comprising a tank for water or fluid to be heated, and a hollow flue at the interior of and extending through said tank for the passage of the heat carrying medium; said flue having an enlargement intermediate its ends and the cross sectional area of the flue at its union with the enlargement being not less than the cross sectional area of said flue directly below, whereby said part of the flue below the enlargement will not act as an injector and prevent the heat carrying medium passing around and in contact with the interior surface of the enlargement.

' 2. A water heater comprising a tank for water or fluid to be heated. and a flue at the interior of said tank having an inlet and outlet and a passage for the heat carrying medium; said flue having a plurality of enlargements, and the cross sectional area of each part of the flue where it connects with an enlargement being of not less cross sec tional area than the cross sectional area of the .part of the flue directly below the same. In testimony whereof I aflix my signature.

THOMAS D. PILCHER. 

